[Z06] Clutch Fluid Bulletin
04-23-2010, 02:45 PM
#1
Clutch Fluid Bulletin
Dealer/tech told me the Z06s need a clutch fluid entire system flush every 2 years. The reservoir flush technique we've seen on our forum is not adequate enough, I have done it multiple times and it was clean in the reservoir. If any of you saw my thread about Comp driving mode and prob with 5th gear shift, this was the cause according to the tech at the dealer. Also, this flush is covered under warranty and it is advised to not even remove the cap after the flush until the next full flush is done next time. They use a super Dot 4 fluid that is longer lasting and very sensitive to moisture. Hope this helps.
04-23-2010, 05:48 PM
#3
Race Director
I figured you'd get some kinda BS like that from the dealer!!!
It's true that your brake system and hydraulic clutch system should be flushed at least every 2 years. Brake/clutch fluid is hygroscopic and absorbs moisture, which lowers the boiling point (hence the dry/wet boiling point specs for hydralulic fluid). That's why you need to flush at least every 2 years.
However, it is WELL ESTABLISHED that the Ranger method keeps your clutch fluid clean. If you go 2 years without doing the Ranger clutch fluid cleaning method (or otherwise flushing the clutch), you'll have black fluid filled with clutch dust (or whatever it is that gets into the fluid).
Good idea to keep the cap on the clutch and brake fluid reservoirs (and your bottles of fluid as well) - the idea being that moist air can quickly transfer its humidity into the hydraulic fluid, but I'm not that **** about it because I'm not convinced that there's an immediate transfer of atmospheric moisture from the air to the fluid. Also, the systems are not hermetically sealed. As the brake pads wear thinner, the pistons extend out further, and the fluid level goes down in the m/c. There is air in the top of the m/c, and there's a vent to allow additional air in as the fluid level drops.
I do the Ranger fluid swap before every track event, and in the winter I do it at least about every 6 weeks when just driving on the street. Like Ranger, I use Prestone DOT 4 in the clutch. The factory fluid in the brake system is a DOT 3 spec, but I use Motul RBF 600 DOT 4 in the brakes for a higher boiling point for the track. The Tech is correct that, in general, the higher the DOT rating the more easily the fluid will absord moisture.
Take a look at this thread:
http://forums.corvetteforum.com/c6-z...he-clutch.html
That's not something I'm going to do to my car 8 or 10 times a year. You can see in that thread that to get access to the clutch bleed valve you need to remove the exhaust and the tunnel plate to get to the valve. That's sure as hell not something I'm gonna let my local dealer do even every 2 years!!!
If you do remove the exhaust and tunnel plate to get to the valve, make sure you install a remote bleed valve so you can bleed the system without doing major wrenching to do a 5 minute clutch system flush.
OR.....just use the Ranger method - IT WORKS!!!!!
If you've been using the Ranger method regularly, then the dealer Tech's claim that your clutch fluid is the problem is BS!
Other than just not hitting the "shift gate" properly, the only thing I can think of that might give you a problem shifting into 5th is if the shift linkage is not aligned properly. But if it's going in nicely sometimes, I don't know why it wouldn't do it all the time.
I do know that Comp Mode or the Ranger clutch fluid swap method ARE NOT the reason for a problem shifting into 5th!!!
There have been a bazillion 4->5 shifts done at high speed with all models of the C6 at high speed events all over the country in the last 5-1/2 years the car has been out, and it just takes a little more care to get it into 5th than the 2->3 straight ahead push.
Good luck getting the problem figured out.
Bob
It's true that your brake system and hydraulic clutch system should be flushed at least every 2 years. Brake/clutch fluid is hygroscopic and absorbs moisture, which lowers the boiling point (hence the dry/wet boiling point specs for hydralulic fluid). That's why you need to flush at least every 2 years.
However, it is WELL ESTABLISHED that the Ranger method keeps your clutch fluid clean. If you go 2 years without doing the Ranger clutch fluid cleaning method (or otherwise flushing the clutch), you'll have black fluid filled with clutch dust (or whatever it is that gets into the fluid).
Good idea to keep the cap on the clutch and brake fluid reservoirs (and your bottles of fluid as well) - the idea being that moist air can quickly transfer its humidity into the hydraulic fluid, but I'm not that **** about it because I'm not convinced that there's an immediate transfer of atmospheric moisture from the air to the fluid. Also, the systems are not hermetically sealed. As the brake pads wear thinner, the pistons extend out further, and the fluid level goes down in the m/c. There is air in the top of the m/c, and there's a vent to allow additional air in as the fluid level drops.
I do the Ranger fluid swap before every track event, and in the winter I do it at least about every 6 weeks when just driving on the street. Like Ranger, I use Prestone DOT 4 in the clutch. The factory fluid in the brake system is a DOT 3 spec, but I use Motul RBF 600 DOT 4 in the brakes for a higher boiling point for the track. The Tech is correct that, in general, the higher the DOT rating the more easily the fluid will absord moisture.
Take a look at this thread:
http://forums.corvetteforum.com/c6-z...he-clutch.html
That's not something I'm going to do to my car 8 or 10 times a year. You can see in that thread that to get access to the clutch bleed valve you need to remove the exhaust and the tunnel plate to get to the valve. That's sure as hell not something I'm gonna let my local dealer do even every 2 years!!!
If you do remove the exhaust and tunnel plate to get to the valve, make sure you install a remote bleed valve so you can bleed the system without doing major wrenching to do a 5 minute clutch system flush.
OR.....just use the Ranger method - IT WORKS!!!!!
If you've been using the Ranger method regularly, then the dealer Tech's claim that your clutch fluid is the problem is BS!
Other than just not hitting the "shift gate" properly, the only thing I can think of that might give you a problem shifting into 5th is if the shift linkage is not aligned properly. But if it's going in nicely sometimes, I don't know why it wouldn't do it all the time.
I do know that Comp Mode or the Ranger clutch fluid swap method ARE NOT the reason for a problem shifting into 5th!!!
There have been a bazillion 4->5 shifts done at high speed with all models of the C6 at high speed events all over the country in the last 5-1/2 years the car has been out, and it just takes a little more care to get it into 5th than the 2->3 straight ahead push.
Good luck getting the problem figured out.
Bob
04-23-2010, 08:05 PM
#4
Melting Slicks
Dealer/tech told me the Z06s need a clutch fluid entire system flush every 2 years. The reservoir flush technique we've seen on our forum is not adequate enough, I have done it multiple times and it was clean in the reservoir. If any of you saw my thread about Comp driving mode and prob with 5th gear shift, this was the cause according to the tech at the dealer. Also, this flush is covered under warranty and it is advised to not even remove the cap after the flush until the next full flush is done next time. They use a super Dot 4 fluid that is longer lasting and very sensitive to moisture. Hope this helps.
So what's the dealer going to charge you for a clutch fluid flush... 3-4 hours @ $100/hour
I'm sure business is slow... so they wanna make money where ever they can.
I'd listen to BEZ06 before i'd listen to any dealer...
04-23-2010, 08:27 PM
#5
BOB -
Where did you get that photo of the DSOM Z crossing Start/Finish at TWS??
never mind - i guess it must be part of the website since i saw it when i wasn't logged in, then did not after i logged in to post up.
Where did you get that photo of the DSOM Z crossing Start/Finish at TWS??
never mind - i guess it must be part of the website since i saw it when i wasn't logged in, then did not after i logged in to post up.
04-23-2010, 09:09 PM
#6
Race Director
There are about 3 or 4 HPDEs here each fall during Oct/Nov/Dec.
Click on the picture and it should link you to a youtube video of a couple laps. Or, I'll post up a better link below.
BTW, the reason you saw it when you weren't logged in, and couldn't see it when you were logged in, is because it's my "signature". You can have a signature that will add stuff to each of your posts.
When you are logged in, you probably have your forum preferences set so that signatures are not displayed. When you were not logged in, the default is for signatures to display if people have one on their posts.
Bob
Last edited by BEZ06; 04-23-2010 at 09:13 PM.
04-23-2010, 09:33 PM
#7
Drifting
Dealer/tech told me the Z06s need a clutch fluid entire system flush every 2 years. The reservoir flush technique we've seen on our forum is not adequate enough, I have done it multiple times and it was clean in the reservoir. If any of you saw my thread about Comp driving mode and prob with 5th gear shift, this was the cause according to the tech at the dealer. Also, this flush is covered under warranty and it is advised to not even remove the cap after the flush until the next full flush is done next time. They use a super Dot 4 fluid that is longer lasting and very sensitive to moisture. Hope this helps.
What I would like to know is, after having them flush your system the "proper" way, is your problem resolved? Please keep us informed.
04-24-2010, 12:18 AM
#9
Safety Car
04-24-2010, 09:20 AM
#10
I figured you'd get some kinda BS like that from the dealer!!!
It's true that your brake system and hydraulic clutch system should be flushed at least every 2 years. Brake/clutch fluid is hygroscopic and absorbs moisture, which lowers the boiling point (hence the dry/wet boiling point specs for hydralulic fluid). That's why you need to flush at least every 2 years.
However, it is WELL ESTABLISHED that the Ranger method keeps your clutch fluid clean. If you go 2 years without doing the Ranger clutch fluid cleaning method (or otherwise flushing the clutch), you'll have black fluid filled with clutch dust (or whatever it is that gets into the fluid).
Good idea to keep the cap on the clutch and brake fluid reservoirs (and your bottles of fluid as well) - the idea being that moist air can quickly transfer its humidity into the hydraulic fluid, but I'm not that **** about it because I'm not convinced that there's an immediate transfer of atmospheric moisture from the air to the fluid. Also, the systems are not hermetically sealed. As the brake pads wear thinner, the pistons extend out further, and the fluid level goes down in the m/c. There is air in the top of the m/c, and there's a vent to allow additional air in as the fluid level drops.
I do the Ranger fluid swap before every track event, and in the winter I do it at least about every 6 weeks when just driving on the street. Like Ranger, I use Prestone DOT 4 in the clutch. The factory fluid in the brake system is a DOT 3 spec, but I use Motul RBF 600 DOT 4 in the brakes for a higher boiling point for the track. The Tech is correct that, in general, the higher the DOT rating the more easily the fluid will absord moisture.
Take a look at this thread:
http://forums.corvetteforum.com/c6-z...he-clutch.html
That's not something I'm going to do to my car 8 or 10 times a year. You can see in that thread that to get access to the clutch bleed valve you need to remove the exhaust and the tunnel plate to get to the valve. That's sure as hell not something I'm gonna let my local dealer do even every 2 years!!!
If you do remove the exhaust and tunnel plate to get to the valve, make sure you install a remote bleed valve so you can bleed the system without doing major wrenching to do a 5 minute clutch system flush.
OR.....just use the Ranger method - IT WORKS!!!!!
If you've been using the Ranger method regularly, then the dealer Tech's claim that your clutch fluid is the problem is BS!
Other than just not hitting the "shift gate" properly, the only thing I can think of that might give you a problem shifting into 5th is if the shift linkage is not aligned properly. But if it's going in nicely sometimes, I don't know why it wouldn't do it all the time.
I do know that Comp Mode or the Ranger clutch fluid swap method ARE NOT the reason for a problem shifting into 5th!!!
There have been a bazillion 4->5 shifts done at high speed with all models of the C6 at high speed events all over the country in the last 5-1/2 years the car has been out, and it just takes a little more care to get it into 5th than the 2->3 straight ahead push.
Good luck getting the problem figured out.
Bob
It's true that your brake system and hydraulic clutch system should be flushed at least every 2 years. Brake/clutch fluid is hygroscopic and absorbs moisture, which lowers the boiling point (hence the dry/wet boiling point specs for hydralulic fluid). That's why you need to flush at least every 2 years.
However, it is WELL ESTABLISHED that the Ranger method keeps your clutch fluid clean. If you go 2 years without doing the Ranger clutch fluid cleaning method (or otherwise flushing the clutch), you'll have black fluid filled with clutch dust (or whatever it is that gets into the fluid).
Good idea to keep the cap on the clutch and brake fluid reservoirs (and your bottles of fluid as well) - the idea being that moist air can quickly transfer its humidity into the hydraulic fluid, but I'm not that **** about it because I'm not convinced that there's an immediate transfer of atmospheric moisture from the air to the fluid. Also, the systems are not hermetically sealed. As the brake pads wear thinner, the pistons extend out further, and the fluid level goes down in the m/c. There is air in the top of the m/c, and there's a vent to allow additional air in as the fluid level drops.
I do the Ranger fluid swap before every track event, and in the winter I do it at least about every 6 weeks when just driving on the street. Like Ranger, I use Prestone DOT 4 in the clutch. The factory fluid in the brake system is a DOT 3 spec, but I use Motul RBF 600 DOT 4 in the brakes for a higher boiling point for the track. The Tech is correct that, in general, the higher the DOT rating the more easily the fluid will absord moisture.
Take a look at this thread:
http://forums.corvetteforum.com/c6-z...he-clutch.html
That's not something I'm going to do to my car 8 or 10 times a year. You can see in that thread that to get access to the clutch bleed valve you need to remove the exhaust and the tunnel plate to get to the valve. That's sure as hell not something I'm gonna let my local dealer do even every 2 years!!!
If you do remove the exhaust and tunnel plate to get to the valve, make sure you install a remote bleed valve so you can bleed the system without doing major wrenching to do a 5 minute clutch system flush.
OR.....just use the Ranger method - IT WORKS!!!!!
If you've been using the Ranger method regularly, then the dealer Tech's claim that your clutch fluid is the problem is BS!
Other than just not hitting the "shift gate" properly, the only thing I can think of that might give you a problem shifting into 5th is if the shift linkage is not aligned properly. But if it's going in nicely sometimes, I don't know why it wouldn't do it all the time.
I do know that Comp Mode or the Ranger clutch fluid swap method ARE NOT the reason for a problem shifting into 5th!!!
There have been a bazillion 4->5 shifts done at high speed with all models of the C6 at high speed events all over the country in the last 5-1/2 years the car has been out, and it just takes a little more care to get it into 5th than the 2->3 straight ahead push.
Good luck getting the problem figured out.
Bob
Ego does not prevent me from accepting the shift problem may be partly technique, but I wanted to find out was it the only reason. I've flushed the clutch at least 4-5x this past year and did so before this event (Ranger method). The tech said that when he flushed the system the lower end came out black at first and then was better. He had heard of this problem before and that 80% of the time it was the clutch fluid, and that the other method was not adequate. I've done 5-6 track days with this new car and the fluid was really black before I started routinely flushing it. Since I've had no other clutch problems, I agree it most likely is my technique. But, why did he still get black fluid out when the reservoir was pretty clean, slightly amber only?
04-24-2010, 09:34 AM
#11
Burning Brakes
[QUOTE=jmzo6;1573861810]Ego does not prevent me from accepting the shift problem may be partly technique, but I wanted to find out was it the only reason. I've flushed the clutch at least 4-5x this past year and did so before this event (Ranger method). The tech said that when he flushed the system the lower end came out black at first and then was better. He had heard of this problem before and that 80% of the time it was the clutch fluid, and that the other method was not adequate. I've done 5-6 track days with this new car and the fluid was really black before I started routinely flushing it. Since I've had no other clutch problems, I agree it most likely is my technique. But, why did he still get black fluid out when the reservoir was pretty clean, slightly amber only? [/QUOTE
What did the dealer charge for the clutch fluid flush?
[/QUOTEWhat did the dealer charge for the clutch fluid flush?
04-24-2010, 09:46 AM
#12
Burning Brakes
Member Since: Feb 2006
Location: Ex BX... Ex NJ... Hello CT!!! CT
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So... How much did the dealer charge you for the lesson learned?!?!?
04-24-2010, 11:56 AM
#13
No charge, all under warranty. Oh, but I did, and smiled all the way to 180mph on the run out of comp mode
04-24-2010, 12:22 PM
#14
Team Owner
I've yet to figure how "clutch dust" gets in the fluid system. Seems to me if the dust can get in, then the fluid can find the same way out, and therefore a leak. Never had this problem with any of my other non GM vehicles with a hydraulic clutch.
04-24-2010, 01:31 PM
#15
Melting Slicks
We suspect the brake dust is clinging to the slave cylinder push rod when it extends, then when it retracts it comes back through the seal and the fluid absorbs it from the push rod.
It really needs to be re-engineered with a proper dust boot on the slave cylinder and an improved seal design. I am guessing it needs a stainless pushrod with a teflon seal and a full dust boot with an acordian design.
For now, a regular flush of the clutch master cylinder works well.
It really needs to be re-engineered with a proper dust boot on the slave cylinder and an improved seal design. I am guessing it needs a stainless pushrod with a teflon seal and a full dust boot with an acordian design.
For now, a regular flush of the clutch master cylinder works well.
04-24-2010, 01:52 PM
#16
Race Director
Dealer/tech told me the Z06s need a clutch fluid entire system flush every 2 years. The reservoir flush technique we've seen on our forum is not adequate enough, I have done it multiple times and it was clean in the reservoir. If any of you saw my thread about Comp driving mode and prob with 5th gear shift, this was the cause according to the tech at the dealer. Also, this flush is covered under warranty and it is advised to not even remove the cap after the flush until the next full flush is done next time. They use a super Dot 4 fluid that is longer lasting and very sensitive to moisture. Hope this helps.
Thanks for the tip!
Going to the dealer for an oil change next week
Will have them check the fluid, swaybrar endlinks as well as o-ring in oil tank as long as I'm there.
04-24-2010, 04:54 PM
#17
Safety Car
Ah well.... All in good fun....
04-24-2010, 05:44 PM
#18
Le Mans Master
I think all this stuff with clutch-fluid is over-rated. From what T56 Rebuilds in Houston told me, you replace the hydraulics every 50K miles anyways, per GM's recommendation. The hydraulics in my WS6 lasted about 90K miles before needing changing. Not bad at all, really. It cost me something like $100 and part of my afternoone. The slave was changed when the clutch was at 80K because the TO bearing was making racket on any shift above 5K. I have never had the dead-pedal, or any other thing like that, maybe I am just lucky, but I doubt it as everything else in the car has fallen apart.
Is the clutch-fluid issue 'vette specific? I am just presuming all T56 and their derivatives would suffer the same, no?
ETA---
I just watched user: "Ranger"s video. Jeez. I have a different opinion, it is definitely an issue and the PM is very simple. Do all T56 cars have this problem, or only 'vettes?
Is the clutch-fluid issue 'vette specific? I am just presuming all T56 and their derivatives would suffer the same, no?
ETA---
I just watched user: "Ranger"s video. Jeez. I have a different opinion, it is definitely an issue and the PM is very simple. Do all T56 cars have this problem, or only 'vettes?
Last edited by BSSN; 04-24-2010 at 06:00 PM.
04-24-2010, 05:47 PM
#19
Burning Brakes
Member Since: Feb 2006
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But under warranty?!?!? Especially after you told them you took the cap off AND you did the Ranger method??? I remember a thread in here somewhere that once the poster told the dealer he opened the cap and did the Ranger method, he wanted to void the warranty.
Thank your "lucky" stars on that one.....
